Retrograde visualization of the portal venous system using CO2 intraarterial digital subtraction angiography.

Carbon dioxide (CO2) intraarterial digital subtraction angiography (IADSA) provides retrograde visualization of the portal vein via a peripheral segmental hepatic artery. IADSA was performed in 12 patients with known hepatic diseases by injecting a peripheral hepatic artery with both CO2 gas and an iodinated contrast medium. The portal vein was constantly visualized only with CO2 IADSA in all patients. The injected CO2 may flow back into the portal vein through an anastomotic system known as the peribiliary or periportal plexus. This new method is safe and useful to image the portal venous system in patients with hepatic malignancy.